Sadly I don't really feel like reading through 20 pages of a thread so I am just going to give my two cents after reading the first few posts and seeing the video.
For pretty much every plot of land there is around a 5-10 foot space between where the owners property ends and the road begins. For my house there is a ditch in front that is the property of the city, in this area there is also a pine tree that they have cut limbs off of almost every single year so they can clean the ditch. With that said it looks like this hoop was placed in that area seeing how there was a sidewalk. In most neighborhoods the sidewalk is city land. From what I saw in the video his land ended where the sidewalk began. So the city is has the right to remove the basketball hoop, though I do not believe the way they went around doing it was the right way to do things. It really does suck for this guy, but at the same time its not too much different if you were to put a basketball hoop up 10 feet into your neighbors lawn, it maybe your hoop, but they have the right to take it down.